ARTll-lClAL STIMULATION To I'KULlFJiKATlUN. 



31 



KKSri/rs WITH Sgl.VUKS. 



As in previous tabli's the records lor s(iuares mikI liolls are kept 

 separate. 



TaoleX. Hesiilt.i of erperlinents <it H'uMijo, Tex., in produciwj proliferation in squares 



by artificial stimulation. 



Tnjutiiifnt o( squares. 



Piiiictun' inadowith No. 12 sterilized nee- 

 dli-; iinscaliMl 



I'uncture made with No. 12 sterilized nee- 

 dle; sealed with shellac 



I'uncture made with hyixnlerinic syringe 

 iKvdIe. sterilized; unsealed 



Finifture made with hyoddermic syringe 

 nrt>d'e, sterilized; sealed with shellac. . 



I'uncture made with hypodermic syringe 

 ntvdie; one-half drop of 2 per cent solu- 

 tion of formic acid inji-cted; unsealed . . 



I'uncture made with hypodermic syringe 

 nei'dle; one-half ilrop'of 2 ix'r ceni solu- 

 tion of formic acid inj;'cted; sealed with 

 shellac 



I'Miieture made with hypodermic syringe 

 niiMlle; one-half drop" of 2 per cent -solu- 

 tion of caustic potash injected; unsealed. 



I'unctun" made with hypoclermic syringe 

 ni>edle; one-half drop of 2 per cent solu- 

 tion of caustic potash injected; sealed 

 wi th shellac 



a g 



3-e 



3* 



Totals and averages 43 



43 



330. 



_ 9 



d c 



el 



Weevil Effi'cts of 

 stages artineial 



found. punctures. 







5" 



12.8 ' 1 



13.4 1 



14.0 2 



12.7 2 



14.0 



13.4 

 12.5 



10.2 



13. U 



•— — o S .- 



100.0 

 0.0 

 0.0 

 28.6 



0.0 



SO.O 

 50.0 



60.0 



040.0 



o Weighted average. 



It must be remembered tbat in all cases these artificial ))uncUires, 

 tlion<rli sealed, resemi)le I'eedintr punctures of the weevil much more 

 closely than tlicy do e*;<T punctures. It is impossible to imitate 

 artificially the natural conditions following; ovi|)osition, the hatching 

 of the ('<;<.:. and the <;radually increasin<i: irritation accom|)anying 

 the <:rowth of the larva. Keally the elfect of a needle puncture 

 upon the tissues j)enetrated is very dillerent from the feediuLT ]Minc- 

 tures of the weevil. The needle simply crushes the cells, |)ushin;j: 

 them aside from its path, and leaviufj the cavity it makes more or 

 less completely lilhvl \\ith sa|) and crushed cells. In th(> weevil 

 puncture the work is ftir more netitly done than it can l>c in any 

 I)unirlin<; imitation. The shar|)ly toothed mandibhvs at the tip of 

 the weevil's snout cut away the ti.ssues smoothly without crushin*; 

 or injurin<; adjoinin<r cells, and the material, beiuix oaten, is entirely 

 removed from the cavity. Icavim: it dry and clean with the adjoinin*; 

 tissues comjiaratively uninjur<'(l. The dilference is really about as 

 ffreat as in a ca.se of the accidental }im|>utation of a limb under si 

 railway train as com])ar(M| with the work of a skilled surgeon. Tiic 



